<!DOCTYPE html>
<html lang="en">
	<head>
		<meta charset="UTF-8" />
		<meta http-equiv="X-UA-Compatible" content="IE=edge" />
		<meta name="viewport" content="width=device-width, initial-scale=1.0" />
		<title>Document</title>
		<style>
			/* @media (min-width: 320px) and (max-width: 375px) {
				.box {
					font-size: 15px;
				}
			}
			@media (min-width: 375px) and (max-width: 414px) {
				.box {
					font-size: 18px;
				}
			}
			@media (min-width: 414px) and (max-width: 480px) {
				.box {
					font-size: 21px;
				}
			}
			@media (min-width: 480px) {
				.box {
					font-size: 24px;
				}
			} */

			/* 利用css的层叠性 和上面的效果相同 */
			@media (min-width: 320px) {
				.box {
					font-size: 15px;
				}
			}
			@media (min-width: 375px) {
				.box {
					font-size: 18px;
				}
			}
			@media (min-width: 414px) {
				.box {
					font-size: 21px;
				}
			}
			@media (min-width: 480px) {
				.box {
					font-size: 24px;
				}
			}
		</style>
	</head>
	<body>
		<div class="box">我是box</div>
	</body>
</html>
